Abstract
Isolated, cultured arterial endothelial cells express an acetylcholine (ACh)-activated K+ current in addition to an inward rectifier current whose conductance is unaffected by ACh. The cholinergic K+ current is specifically blocked by atropine (1 microM) and shows single saturation kinetics with ACh (half-maximal stimulation 51 nM ACh). Unlike the cardiac muscarinic receptor-gated K+ channel, its stimulation appears independent of a pertussis toxin-sensitive GTP-binding protein. Activation of the endothelial muscarinic K+ current resulting in hyperpolarization may represent an initial component of the vasodilatory effect of ACh.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Acetylcholine / pharmacology
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Animals
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Aorta / cytology
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Aorta / metabolism*
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Aorta / physiology
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Calcium / pharmacology
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Cattle
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Cells, Cultured
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Dose-Response Relationship, Drug
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Electric Conductivity
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Endothelium, Vascular / cytology
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Endothelium, Vascular / metabolism*
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Endothelium, Vascular / physiology
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GTP-Binding Proteins / metabolism
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Ion Channels / physiology*
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Kinetics
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Membrane Potentials
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Potassium / metabolism*
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Receptors, Muscarinic / metabolism
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Receptors, Muscarinic / physiology*
Substances
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Ion Channels
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Receptors, Muscarinic
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GTP-Binding Proteins
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Acetylcholine
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Potassium
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Calcium